Internet access mode

Question 1: How many ways to surf the Internet? Dial-up access to the internet through a modem

Computer users connect to the public telephone network through the modem, then connect to the ISP through the public telephone network, and connect to the Internet through the host of the ISP. Before establishing the dial-up connection, they apply to the ISP (usually the local telecommunications department in China) for the right to use the dial-up connection, and get the account number and password. Before surfing the Internet, they need to dial the account number and password. Dial-up Internet access mode is also called dial-up IP mode, because dial-up Internet access mode will be dynamically assigned a legal IP address. A special communication protocol, SLIP or PPP, should be used between users and ISP.

Dial-up internet access costs less, but its function is much stronger than that of dial-up analog terminal, which is suitable for ordinary families and individual users. The speed is slow, because it is limited by the hardware conditions of telephone lines and related access equipment, generally around 56 K.

Access to the internet through ISDN

ISDN is the abbreviation of integrated services digital network, which provides end-to-end digital connection network. In addition to supporting telephone services, it can also support the transmission of fax, digital and image services in the network. ISDN private line access is also called single line access, because it can realize integrated services integrating voice, data and image communication through a telephone line. ISDN connection is connected to ISP through telephone network through network terminal NT, user terminal and ISDN terminal adapter TA, but it needs to be emphasized that this is different from dial-up Internet access, where digital signals are transmitted on telephone lines.

Because ISDN adopts digital transmission technology, ISDN line has strong anti-interference ability, high transmission quality, fast and convenient speed, and can support many different devices. The highest network speed can reach128k/s.

Third, get online through DDN special line.

DDN is the abbreviation of digital data network. It is a digital transmission network that uses digital transmission channels such as copper cable, optical fiber, digital microwave or satellite to provide permanent or semi-permanent connection circuits and mainly transmits digital signals. When it is connected to the Internet, it is connected to ISP through DDN special line, and then connected to the Internet through ISP. When LAN connects to the Internet through DDN private line, it is generally necessary to use baseband modems and routers.

DDN provides point-to-multipoint connection, which is suitable for broadcasting and sending information, centralized control and other services, and is suitable for large enterprises. Adopt digital circuit, with high transmission quality, small time delay, and the communication rate can be selected as required; The circuit can be automatically circuitous with high reliability.

Access to the internet through xDSL

DSL is a digital subscriber line technology, which can use twisted pair to transmit data at high speed. There are many existing DSL technologies, such as HDSL, ADSL, VDSL and SDSL. I said that telecommunications provided users with HDSL and ADSL access technologies. Take ADSL as an example here. ADSL stands for Asymmetric Digital Subscriber Line. It uses advanced digital processing technology to separate the frequency bands of upload channel, download channel and voice channel, and simultaneously transmit data of three different frequency bands on a telephone line, so that digital signals and analog signals can be transmitted simultaneously on the telephone line. Its connection is that the host connects the telephone line through DSL modem, then connects to ISP, and connects to the Internet through ISP.

ADSL provides a broadband network with download transmission bandwidth of up to 8Mbps and upload transmission bandwidth of 64kbps to 1Mbps. Compared with dial-up Internet access or ISDN, it lightens the load of telephone exchange, does not need to dial, belongs to private Internet access, and does not need to pay extra telephone charges.

Access the Internet through a cable modem.

At present, the cable TV network in China is all over the country. Now we can use some special equipment to convert the signal of this network into computer network data information. This device is Cable Modem, which is an analog signal transmitted by cable TV network. We convert digital signals into analog signals through cable modems, so that they can be transmitted with TV signals through cable TV networks. On the user side, we use cable separator to separate TV signal and data signal.

Using this method, the connection speed is fast, the cost is low, and asymmetric connection is provided. This method is the same as using ADSL, users do not need to dial ... >; & gt

Question 2: What are the four ways to surf the Internet? 1. Ordinary dial-up access is very convenient, as long as you can use telephone lines and modems.

2, ADSL dial-up access, you need to apply for it, you need a phone and ADSL modem, usually a monthly or annual service.

3, residential broadband access, many service providers, first fiber access to the community, and then distributed to households.

4, wireless Internet access, suitable for notebook computers, with wireless Internet access, you need to buy Unicom's CDMA or mobile GPRS card.

Question 3: How many ways are there to surf the Internet? At present, there are several common access methods to choose from in China.

1.PSTN public telephone network

This is the easiest way to achieve and the cost is low. There is only one telephone line and one account that can connect to the ISP. But the disadvantages are low transmission speed and poor line reliability. It is suitable for offices and small enterprises with low reliability requirements. If there are many users, multiple telephone lines can work together to improve the access speed.

2. Integrated Services Digital Network

At present, it is rapidly popularized in China, and the price has dropped sharply. In some places, the installation fee is even free. 128 kbit/s dual-channel speed, fast connection and reliable line can meet the needs of small and medium-sized enterprises to browse and send and receive emails.

And enterprise VPN can be established through ISDN and Internet. This method is cost-effective, and most cities in China have ISDN access services.

3. Asymmetric digital subscriber line

Asymmetric digital subscriber loop can provide downlink transmission of 1.5 ~ 8 mbit/s and uplink transmission of 10 ~ 64 kbit/s on ordinary telephone copper cable, which can be used for video conference and video program transmission, and is very suitable for small and medium-sized enterprises. However, there is a fatal weakness: the line distance between the user and the switching room of telecommunications cannot exceed 4 ~ 6 km, which limits its application scope.

4.DDN special line

This method is suitable for applications with high bandwidth requirements, such as corporate websites. It also has a feature of high speed, ranging from 64 kbit/s to 2 mbit/s, but because the whole link is monopolized by enterprises and the cost is very high, SMEs have few choices.

This line has many advantages: fixed IP address, reliable line operation, permanent connection and so on. However, the cost performance ratio is too low, and this method is not recommended unless the user has sufficient funds.

5. Satellite access

At present, some Internet service providers in China have launched satellite access to the Internet. Suitable for users who need high bandwidth in remote places. Satellite users generally need to install a VSAT, including antennas and other receiving equipment. The downlink data transmission rate is generally around 1 Mbit/s, and the uplink is connected to ISP through PSTN or ISDN. Terminal equipment and communication costs are relatively low.

6. Optical fiber access

Some cities have built high-speed metropolitan area networks (MAN), with the backbone network rate reaching tens of Gbit/s, and broadband access has been promoted. The optical fiber can be laid on the user's roadside or in the building, and the access rate can reach more than 100 Mbit/s, which is suitable for large enterprises.

7. Wireless access

Due to the high cost of laying optical fiber, some cities provide wireless access for users who need broadband access. Users connect with ISP through high-frequency antenna, the distance is about 10km, and the bandwidth is 2 ~ 1 1 mbit/s, which is low in cost, but limited by terrain and distance, so it is suitable for users not far from ISP in the city. Very cost-effective.

8. Cable modem access

At present, China's cable TV networks are all over the country, and many cities provide cable modems to access the Internet, and the speed can reach more than 10 Mbit/s, but the working mode of cable modems is * * * to enjoy bandwidth, so the speed may drop in a certain period of time.

The above eight domestic access methods have their own advantages and disadvantages, and each has its own scope of application.

Question 4: Briefly describe several main ways of surfing the Internet. There are four common Internet access modes: dial-up access mode, dedicated line access mode, wireless access mode and LAN access mode.

A dial-up access mode: ordinary modem dial-up mode ISDN dial-up access mode ADSL virtual dial-up access mode.

B private line access mode: cable modem access mode DDN private line access mode optical fiber access mode.

C wireless access mode: GPRS access technology Bluetooth technology (widely used in mobile phones)

LAN access mode: proxy server

General Internet connection methods include: modem (analog line) dial-in, ISDN (integrated services digital network), Cable Modem, ADSL, DirectPC, ADSL PPPoE, LAN to LAN, etc.

Question 5: What are the common ways to surf the Internet? 1.PSTN dialing: the most widely used.

Public switched telephone network

2.ISDN dialing: Call the Internet correctly.

integrated services digital network (ISDN)

3.DDN special line: for group enterprises.

DDN is the abbreviation of English digital data network.

4.ADSL: personal broadband fashion

Asymmetric digital subscriber line

5.VDSL: high-speed broadband access

VDSL is faster than ADSL.

6. Cable modem: used for wired network.

cable modem

7. Passive optical network access

PON (Passive Optical Network) technology is a point-to-multipoint optical fiber transmission and access technology.

8.LMDS access: wireless communication

This is a wireless access technology that can be used for residential broadband access at present.

9. LAN: mature technology and low cost.

LAN access is to use Ethernet technology, using optical cable+twisted pair to comprehensively wire the community.

Question 6: What are the ways to surf the Internet? Internet access mode

There are many ways to access the Internet. The following is a detailed introduction to the access mode that individual users are most concerned about, that is, if you own a PC, how to access the Internet?

1. dial-up connection

(1) Normal dialing mode

(a) Dialing up the Internet in this way requires a device: a modem.

It's the abbreviation of English modem. Chinese is commonly known as "cat". Because the ordinary telephone network transmits analog signals, while the computer processes digital signals. If the process of converting digital signals into analog signals is called modulation, then the opposite process is demodulation. Modems play this role. There are two types: built-in and external. The built-in modem is a card inserted into the computer motherboard; Many brands of computers are pre-installed with built-in modems. If it is added later, many people will choose an external modem. Pre-installed built-in modems usually have drivers installed. Just connect the telephone line connector (commonly known as crystal head, because it is white and transparent) to the interface provided by the modem behind the main chassis. The external modem is to plug the telephone line into the modem, and the accessory comes with the connecting cable between the modem and the computer. One end of the connecting cable is connected to the modem, and the other end is connected to the serial interface on the computer host. You can refer to the instruction manual of the accessories. As for installing drivers, MODEM are all so-called PnP devices (plug and play), and windows will automatically detect the installation. In short, you don't need any professional knowledge, and novices can do it.

(b) An Internet account provided by an ISP is required.

ISP is the abbreviation of Internet Service Provider. Because of the openness of the Internet, any company or individual can invest in equipment, set up websites, provide access services and become an ISP if they want. In China, people usually choose China Telecom 163 as their ISP. What did ISP offer you? The dial-up number is 163, which is unified throughout the country. We also provide you with their approved user name and password. This service is provided by local telecom departments and business counters. You just need to fill in an application form, bank account number, etc. There is no application fee now. Some brand machine or modem suppliers may also provide you with an online account for free.

If the application is troublesome, Guangdong Telecom, a subsidiary of China Telecom, provides application-free access by dialing: 96333, user name: 169 and password: 169. The whole province is unified, and the internet access fee is included in the payment account of the phone you connected.

(c) Networking

Click the Internet Explorer icon on the desktop → right-click the selected object → select properties to open the Internet property selection dialog window, as shown in Figure 4. 1.

(2) Single-wire communication (ISDN)

ISDN (Integrated Services Digital Network), whose Chinese name is Integrated Services Digital Network, is commonly known as "One Line Communication" by China Telecom. It is a new way of communication that rose in the international arena in the late 1980s. Only one telephone can be connected to the same pair of ordinary telephone lines, so the original dial-up internet access means that you can't make a phone call at this time. After applying for ISDN, you can use several terminals at the same time through a conversion box called NT. You can surf the Internet while making phone calls or communicating with other data. Although it is still an ordinary telephone line, NT's converter box provides users with two standard 64KB/S digital channels, namely the so-called 2B+D interface. The TA port is connected to the telephone, and the NT port is connected to the computer. The maximum transmission rate it allows is 128KB/S, which is three to four times that of ordinary MODEM. Therefore, its popularity is, in a sense, a major innovation in the traditional concept of communication. Installation and communication costs are similar to ordinary telephones. It has only been opened in major cities in China in the past year or two. You can also apply at the business outlets of the Telecommunications Bureau. Of course, this has become the first way to dial up the Internet at present.

2. LAN connection

If you want to connect your computer to the LAN, you need to install a network card and plug it into the expansion slot of the motherboard. Then connect the network card interface with the access point of the LAN with twisted pair. At present, our school has two ADSL lines to provide Internet access. Every computer on the local area network can connect to the Internet through a proxy by running some proxy software on a server or computer that has been connected to the Internet. Right ... >>

Question 7: What are the Internet connection methods? 1. Dial-up Internet access is the most widely used Internet access method in the past. It connects computers to the Internet through modems and telephone lines, and further accesses network resources. The advantages of dial-up Internet access are simple installation and low one-time investment cost. Users only need to get an Internet account from an ISP (network operator) and then connect the necessary hardware settings. Disadvantages are slow speed, poor access quality, and users can't answer the phone when surfing the Internet. This way of surfing the Internet is suitable for individual users who spend less time surfing the Internet. 2.ISDN Internet access mode ISDN is the abbreviation of integrated service digital network, that is, narrow-band integrated service digital network, commonly known as "one-line communication", which also uses existing telephone lines to access the Internet. This way of surfing the internet has the following characteristics: multi-service: telephone, fax, videotex, videophone and other services can be realized. Digitization: provide end-to-end digital connection, realize end-to-end digitalization, and exchange information with high quality. Ease of use: only one network interface is needed, and a unified number is used, and different kinds of multiple terminals can be connected on this interface. The disadvantage of using ISDN to surf the Internet is high cost, because using ISDN requires special terminal settings (including network terminal NT 1 and ISDN adapter). 3. Broadband ADSL is called asymmetric digital subscriber line in English, that is, asymmetric digital subscriber line. ADSL technology is a high-speed data transmission technology on ordinary telephone lines, which uses frequencies that have never been used on telephone lines, so it can break through the speed limit of 56kbps of modems. The main feature of ADSL technology is that by installing ADSL equipment at both ends of the line, we can make full use of the existing telephone network and provide users with high-speed broadband services. In addition, ADSL and ordinary telephone can be stored on a telephone line, and ADSL transmission can be carried out while answering and making calls on an ordinary telephone line without affecting each other. ADSL broadband Internet access has the advantages of star structure, good confidentiality, high safety factor, high speed and low price. The disadvantage is that analog signals cannot be transmitted. 4. Fiber-optic Internet access refers to replacing copper-core telephone lines with fiber-optic cables and connecting to the Internet through fiber-optic transceivers, routers and switches. This way of surfing the Internet can make the download speed reach 6Mbps and the upload speed reach 640kbpS. The advantages of optical fiber Internet access are exclusive bandwidth, stable performance, low upgrade cost, no electromagnetic interference, low loss, strong security and confidentiality, and long transmission distance. Wireless Internet access means that you don't need to connect to the Internet through telephone lines or network cables, but through communication signals. As long as the user is located within the radio wave coverage of the wireless access port and provides a compatible wireless network card, he can easily access the Internet.

Question 8: Four commonly used Internet access methods 1, ordinary dial-up Internet access, convenient, as long as a telephone line and a modem can talk, there is no need to apply. The price is one hour in 4.5 yuan, and the speed is poor, so it is suitable for temporary surfing the Internet and sending and receiving some mails.

2, ADSL dial-up access, you need to apply for it, you need a telephone and ADSL modem, usually a monthly or annual service, ranging from 500 to 1000. Fast speed, suitable for people who surf the internet in fixed places for a long time, telecom, Netcom and other service providers.

3, residential broadband access, many service providers, first of all, optical fiber access to the community, the access fee seems to be 2000 yuan per month, pay attention to this trillion and ADSL trillion is not the same. Household, the more people who use the internet faster, the cheaper the price. Of course, the more speed points, the lower the relative speed will be.

4, wireless Internet access, suitable for laptops, with wireless Internet access, you need to buy Unicom's CDMA or mobile GPRS card, which is slow and expensive. You can only browse simple information and send and receive some emails.